1. Field of the Invention
The invention relates to a mobile terminal and, more particularly, to a system and method for controlling a display unit of a mobile terminal.
2. Background of the Related Art
In general, screen information (data) to be displayed on a display unit of a mobile terminal is configured and stored in an external memory such as a Random Access Memory (RAM). There are two methods typically used to display the screen information stored in the external memory.
A first related art display method is shown in FIG. 1. In this first method, a controller, such as a central processing unit (CPU) is used to configure and output the screen information. More specifically, as shown in FIG. 1, a controller 13 records screen data in a screen output buffer (not shown) of an external memory 12, reads the screen data from the screen output buffer, and outputs the data to a display unit 11.
However, this reading/writing of display data from/into the external memory 12 and outputting data to the display unit 11 requires multiple clock cycles, thus restricting performance of the display unit 11. More specifically, by using this first display method, the reading/writing time associated with the external memory 12 and the controller 13, as well as a transfer rate between the external memory 12 and the controller 13, limit the display speed, and thus the type of display unit that can be used with the related art mobile terminal.
A second related art display method is shown in FIG. 2. In this second method, screen data is configured by a controller and output by an external memory. More specifically, as shown in FIG. 2, a controller 23 configures screen data in a screen output buffer (not shown) of an external memory 22, and the external memory 22 outputs the configured screen data directly to the display unit 21.
This second related art display method is advantageous in that a lesser number of clock cycles are required for the transfer of screen information, and display data can be output to the display unit 21 more quickly than in the first related art display method.
However, this second related display method suffers deficiencies similar to this first method, in that performance of the display unit is still somewhat limited by the reading/writing time required by the external memory 22, a transfer rate between the external memory 22 and the controller 23, and a transfer rate between the external memory 22 and the display unit 21.
Thus, when screen data is configured in an external memory in accordance with these related art display methods, performance of the display unit is limited by the performance of the external memory and the interface speed. That is, since the output speed of the display unit is limited by a reading/writing time from/into the external memory by the controller, a data transfer rate between the external memory and the controller, and a data transfer rate between the external memory and the display unit, the related art mobile terminal cannot take advantage of the enhanced display capabilities associated with a high performance display unit.